Releasable clasp



March 26, 1968 J. R. METZ HELEASABLE CLASP Filed Jan.

INVENTOR.

Fi i

Joseph E Me tz United States Patent 3,374,512 RELEASABLE CLASP loseph R. Metz, Ridgefield, Conn, assignor to Norco, Inc, Ridgefield, Conn, a corporation of Connecticut Filed Jan. 3, 1966, Ser. No. 518,063 Claims. (Cl. 24241) ABSTRACT OF THE DISCLOSURE Heavy duty releasable clasp comprising a hook formation having a spring-charged locking slide bolt to close the gap of the hook. A cross release bolt has a cam connection with the locking bolt and is adapted to be struck a hammer blow from either side of the hook formation to retract the locking bolt and release a part held captive in said formation.

This invention relates to heavy duty releasable clasps, especially those which may be released while under heavy load, by means of a blow from a heavy tool or instrument.

Objects and features of the invention are to provide an improved heavy duty readily releasable clasp wherein only few and relatively simple, relatively inexpensive parts are required, said parts operating according to approved mechanical principles to produce a rugged and highly reliable clasp having an especially powerful release action; to provide a clasp as above, which may be advantageously released by impact forces, such as produced by a hammer blow, and one wherein lesser impact forces are required as the load is increased; a clasp as above, wherein assembly of the parts is especially simple, quick and economical; a clasp as above, wherein retention of the working parts in their operative positions is simply and reliably effected, wherein great reliability and freedom from failure or malfunctioning is had, wherein simple and straightforward mechanical movements are utilized, and wherein blows from either of opposite directions will be equally etfective to accomplish a release; a clasp of the kind indicated, which is especially adapted to withstand impact-force actuation without detriment or failure, and one which permits quick, facile attachment without requiring actuation of the impact-receiving release members.

Other features and advantages will hereinafter appear.

In the drawings:

FIG. 1 is a side elevational view of a heavy duty clasp as provided by the invention, engaged with a portion of a cooperable part or member which is being releasably held thereby.

FIG. 2 is a top plan view of the clasp of FIG. 1 and portion of the cooperable member.

FIG. 3 is a top plan view of a locking bar as employed in the clasp.

FIG. 4 is a side elevational view of the locking bar of FIG. 3.

FIG. 5 is a bottom plan view of the locking bar of FIGS. 3 and 4.

FIG. 6 is a top plan view of one of two identical release bars as employed in the clasp of FIGS. 1 and 2 and which are cooperable with the locking bar of FIGS. 3, 4 and 5.

FIG. 7 is a side elevational view of the release bar of FIG. 6.

FIG. 8 is an end elevational view of the release bar of FIGS. 6 and 7.

Considering first FIGS. 1 and 2, the heavy duty clasp is indicated generally by the numeral 10, said clasp being engaged with a cooperable piece of equipment or machine part which may comprise a pair of spaced arms 12, 14

3 ,3 74,5 12 Patented Mar. 26, 1 968 having aligned openings, through which a clevis pin 16 passes and in which the latter is held.

The heavy duty clasp comprises a body portion 18 having a bifurcated rearward end comprising spaced arms 20, 22 in which there is secured a clevis pin 24 by any usual means, such as a cotter 26. The spaced arms 20, 22 and the clevis pin 24 enable the clasp 10 to be secured to a structure intended to be releasably fastened to the equipment comprising the arms 12, 14 and the clevis pin 16.

The body 18 of the clasp 10 comprises a hook formation 28 including a bill portion 39, said formation being shaped to provide a gap 32 at its underside, which is adapted to laterally receive the clevis pin 16, as by passing the hook 26 downward over the pin or else by passing the pin 16 and arms 12, 14 upward into the illustrated cooperable relationship of FIG. 1. It will be understood that such relationship elfects an attachment of the clasp 10 to the equipment portions 12, 14 and 16.

The body portion 18 has a cylindrical guide channel 34 which opens into the gap 32 of the hook, and also has a second but rectangular guide channel 36 which crosses the first guide channel 34, shown as at right angles. In the guide channel 34 there is longitudinally movable a locking bar 38, FIGS. 3, 4 and 5, including a nose portion 40 having a sloping camming bottom surface 42 and a hollow or curved upper surface .4.

The nose portion 49 is adapted to protrude into the gap 32 of the hook formation 28 when the locking bar is in its advanced position as illustrated in FIGS. 1 and 2, or else to be retracted or removed from such gap when the locking bar is in a retracted position shifted to the left (as viewed in FIG. 1) from the position shown. Such retracted position of the locking bar will release the clevis pin 16 for removal from the hook formation 28, whereas the advanced position of the locking bar, as shown, securely holds the clevis pin 16 in the illustrated position occupying the hook formation.

Yielding means comprising a spring 46 are provided in the first guide channel 34, such spring normally urging the locking bar 38 to the advanced, locking position indicated. A flat plug 48 is disposed in the leftmost end of the guide channel 34, being held in place by a cross pin 59 and engaging the leftmost end of the spring 46, considering FIG. 1, thereby constituting an abutment for such spring and preventing it from leaving the guide channel 34.

In accordance with the present invention, a novel release mechanism is provided, especially adapted to be actuated by impact, as by the blow from a hammer, thereby to effect a sudden and powerful retraction of the locking bar 38, and one which is also reliable despite heavy load forces to which the locking bar may be subjected from the clevis pin 16. The said release means comprises cam surfaces 52 and 54 provided on the locking bar 38 at the innermost end portion thereof, said bar having an intermediate portion 56 of reduced cross section connecting the innermost camming end with an enlarged head portion 58 carrying the nose 4%).

Cooperable with the cam surfaces 52, 54 are camming surfaces 60 of a pair of identical release bars 59 only one of which is illustrated in FIGS. 6, 7 and 8. Each of the release bars 59 comprises an enlarged outermost head portion 62, relatively slim intermediate portion 64 and an innermost camming end portion 66. The two release bars 59 are disposed in the transverse or second guide channel 36 of the body it) with their head ends 62 outermost and protruding from the sides of the body portion. One intermediate portion 64 and cam end 66 extends above the connecting or shank portion 56 of the locking bar 38, whereas the other portion 64 and cam end 66 extends below the connecting or shank portion 56 of the locking bar. The cam surface 60'of one release 1 channel 36, and the engagement between the coopermember 59 engages the cam surface 52 of the locking bar, and the cam surface 66 of the second release bar engages the other cam surface 54 of the locking bar; Each release bar 59 hasa square shoulder 68 comprising the inner surface of the head portion 62, and the shoulder 68 of any one bar 59 is engaged by a squared, flat inner end surface 70 of the other bar 59.

.It will be understood that with such construction the release bars 59 are retained in the operative positions illustrated in FIG. 2 by virtue of engagement of the cooperable camming surfaces of the three bars involved,

with the locking bar 38 being continually under the action of the compression coil spring 46. Also, if either one of the release bars 59 isforced inward, the engagement between the surfaces 68, 70 of the release bars will causethe other release bar to shift in a manner whereby the camming surface 60 thereof will cam inward the locking bar 38. Thus, vsuch release action is characterized by compressional stress in the portion 64 of the release bar 59 which is being forced inward, as distinguished from any tensional stress in said section. Moreover, the retracting movement of the locking bar 38 involves. the unidirectional simultaneous action of both of the release bars 59, regardless of which one (by itself) is being forced inward.

In a jumbo, heavy duty clasp such as. provided by the present invention, it is desired that a sudden and very powerful retracting action of the locking bar 38 will be a a powerful hammer blow without mushrooming or deformation, the head portions 62 of such bars are provided with impact faces 74 of reduced diameter, and

preferably the hardness and composition of the metal from which the release bars are fabricated provide a blows without danger of cracking, breaking, bending,

etc. 7 Referring to FIG. 2 it will be seen that either one of the two protruding head portions 62 is in a position wherein the impact surface 74 thereof is readily accessible to receive such a hammer blow. The force and energy of this blow, working through the cooperable camming surfaces of the release and locking bars, will result in a sudden and unfailing retraction of the locking bar 38 even thoughthe latter is experiencing an extremely heavy working load from its engagement with the clevis pin 16. In operation, the release bars 59 experience mostly compressive forces, whereas the locking bar 38 experiences a tensional retracting force in the shank or intermediate portion 56 thereof.

Of course, upon release and removal of the clevis pin 16, the action of the return spring 46 will return the locking and release bars to the normal positions illustrated in FIGS. 1 and2.

Entry of the clevis .pin 16 fully into the gap 32 f the hook formation 28 may be effected in a forceful manner, by engagement of such pin with the camming surface ,42 of the locking bar, and such action will eifcct a retraction of the locking bar against the action of the spring 46, without requiringiany corresponding movement on the part of the release bars 59 for the reason that clearance is provided inwardly of the head portion 56 of the locking bar, for the adjoining portions of the release bars. The rectangular cross sectional configuration of the release bars 59 will prevent their turning the guide able cam surfaces will prevent turning of the locking bar 38 whereby the latter may be formed from round stock. Thus, the guide channel 34 will be of circular cross section, whereas the second guide channel 36 is of rectangular cross section. V p

The direction or axis of the first channel 34 makes an obtuse angle with respect to the direction of removal of the clevis'pin 16, or with the vertical axis shown in FIG. 1, as measured externally of the clasp body 10. This angle is indicated at X in FIG. 1. A value of approximately 105" as shown in the drawings has been found desirable in practice, for example. As understood at present, it isbelieved that such obtuse angle in conjunction with the slope (with respect to the direction of'the channel 34) of the chord subtending the area of contact between the pin 16 and the arcuate face 44 of the locking pin results in the fact that a less forceful hammer blow on one of the release bars 59 is'required to efiect release as the load between the pin 16 and bar 38 increases. It will be seen that the rounded nature of the pin 16, acting on the nose portion of the locking bar 38 results in the latter being cammed by the pin 16 to its retracted, releasing position once such retraction has been initiated by the hammer blow onone of the release bars 59. Thus a greater load on the pin 16 will result in the bar 38 being more forcibly retracted by said camming action, since the opposition of the spring 46 always uniformly follows its characteristic curve and does not deviate therefrom. Therefore greater loads on the pin 16 insure quicker release, once such release is started. A factor in this facilitated release is the angle or slope of the inner side wall of the jaw V which is opposite the nose 40 of the locking bar. As

' toughness and resistance to deformation from hammer seen in FIG. 1, this inside wall diverges at an angle of a roughly 12 with respect to its opposite wall, and extends down and to the right, as it reaches the bill of the hook formation. This'helps to effect a quick and easy release of the pin 16.

It is noted also that the rounded tip of the nose 40, which has sloping surfaces on its convexity with respect to the axis of the first channel 34, quickly comes in contact with the clevis pin 16 immediately after the initiation of the release operation, and these surfaces by themselves and also in conjunction with the said sloped inner wall of the bill of the hook formation, result in a camming action by which the release of the pin 16 from V have provided a novel and improved jumbo or heavyduty releasable clasp device wherein the release may be readily and reliably effected by the employment of hammerblows, which fully overcome the resistance to release which the clasp may experience from theload being carried.

Variations and modifications may be made within the scope of the claims, and portions of the improvement may be used without others.

I claim:

1. A heavy duty releasable clasp comprising, in combination: 1

(a) a body having a hook formation, there being a first guide channel which opensinto the gap of the hook, and there being a second guide channel crossing said first guide channel,

(b) a locking bar movable longitudinally in said first guide channel between an advanced position enabling one end thereof to protrude into said hook gap to lock a cooperable. member received therein, and a retracted position wherein the end is withdrawn from the ga'p for freeing said member,

(c) yieldable means urging said locking bar to ad- 'vanced position, a 7

(d) a pair of separate release bars slidable in said second guide channel and abutting each other, said release bars having oppositely located outer exposed and accessible ends,

(e) cooperable cam means connected with said three bars, effecting a retraction of the locking bar in response to driving of one or the other release bar inwardly of said body, the release bar which is not driven inwardly being moved outwardly of the body and constituting an intermediary member of said cam means, acting between the driven release bar and the locking bar, and

(f) hammer-blow-resistant formations on the outer ends of the release bars, preventing mushrooming and malformation of said ends whereby a sudden and powerful retraction of the locking bar may be effected without damage to a release bar by striking the latter a blow with a heavy tool.

2. A heavy duty releasable clasp comprising, in combination:

(a) a body having a hook formation, a first guide channel which opens into the gap of the hook, and a second guide channel crossing said first guide channel,

(b) a locking bar movable longitudinally in said guide channel between an advanced position enabling one end thereof to protrude into said hook gap to lock a cooperable member received therein, and a retracted position wherein the end is withdrawn from the gap for freeing said member,

c) yieldable means urging said locking bar to advanced position,

(d) a release bar slidable in said second guide channel,

having an outer exposed and accessible end,

(e) cooperable cam means connected with said bars, effecting a retraction of the locking bar in response to movement of the release bar inwardly of said body, and

(f) a hammer-'blow-resistant formation on the outer end of the release bar, preventing mushrooming and malformation of said end whereby a sudden and powerful retraction of the locking bar may be effected without damage to the release bar by striking the latter a blow with a heavy tool,

(g) the axis of the first guide channel makes an obtuse angle with the direction of removal of said cooperable member, measured externally of said clasp body,

(h) said one end of the locking bar having a surface which is engageable with said cooperable member and which slopes with respect to the direction of the first guide channel, thereby providing a camming action which results in lesser release forces being required as the load on the end of the locking member is increased.

3. A releasable clasp as in claim 2, wherein:

(a) the hook formation has divergent inner walls,

(b) the one inner wall which is located opposite to the locking bar having a slope with respect to the axis of the first guide channel which enables the load on the cooperable member to facilitate release of the member from the hook formation.

4. A releasable clasp as in claim 3, wherein:

(a) the said one inner wall of the hook formation makes an angle of roughly 12 with the opposite inner wall.

5. A releasable clasp as in claim 2, wherein:

(a) said surface of the locking bar which engages the cooperable member is concave.

6. A heavy duty releasable clasp comprising, in combination:

(a) a body having a hook formation, a first guide channel which opens into the gap of the hook, and a second guide channel crossing said first guide channel,

(b) a locking bar movable longitudinally in said guide channel between an advanced position enabling one end thereof to protrude into said hook gap to lock a cooperable member received therein, and a retracted position wherein the end is withdrawn from the gap for freeing said member,

(0) yieldable means urging said locking bar to advanced position,

((1) a release bar slidable in said second guide channel,

having an outer exposed and accessible end,

(e) cooperable cam means connected with said bars, effecting a retraction of the locking bar in response to movement of the release bar inwardly of said body, and

(f) a hammer-blow-resistant formation on the outer end of the release bar, preventing mushrooming and malformation of said end whereby a sudden and powerful retraction of the locking bar may be effected without damage to the release bar by striking the latter a blow with a heavy tool,

(g) said cooperable cam means comprising a cam on the locking bar and a cam piece engaged with said cam and having an abutting connection with said release bar, and

(h) means on said release bar, blocking its withdrawal from said second guide channel in a direction tending to separate said abutting connection,

(i) said cam piece constituting part of a second release bar carried in said second guide channel,

(j) said means blocking withdrawal of the first-mentioned release bar com-prising a cam thereon, and comprising an additional cam engageable therewith and disposed on the locking bar.

7. A releasable clasp as in claim 6, wherein:

(a) an abutting connection is provided between said additional cam and said second release bar,

(b) both said release bars having exposed exterior ends accessible at opposite ends of the second channel for striking by a hammer.

8. A releasable clasp as in claim 7, wherein:

(a) the locking bar has an intermediate portion of reduced cross section and an inner end carrying the cams thereof,

(b) said cams of the locking bar comprising surfaces acting in opposite directions,

(c) said release bars extending past the intermediate portion of the locking bar and having the cams thereof carried on their inner end portions.

9. A releasable clasp as in claim 8, wherein:

(a) each release member comprises a rectangular head portion constituting the outer end thereof, and a fiat blade-like portion along one side, said bladelike portion diverging to a wide inner end the Width of which is commensurate with that of the head,

(b) said second guide channel having a rectangular cross-sectional shape in which the bar heads slidably tit.

10. A releasable clasp as in claim 9, wherein:

(a) the locking bar is cylindrical and has a flatted portion intermediate its ends,

(b) said first guide channel being of circular cross section,

(c) said release bars extending on opposite sides of the fiatted portion of the locking bar and preventing turning of the latter in the said first guide channel.

References Cited UNITED STATES PATENTS 382,611 5/1888 Howe 24239 1,503,541 8/1924 Lintott et a1. 1,653,058 12/1927 Nelson 24239 1,740,782 12/1929 Ratigan 24238 3,036,353 5/1962 Min-utoli 24230 DONALD A. GRIFFIN, Primary Examiner. 

